[BEIJING] Chinese scientists have developed a method to help people avoid the threat of landslides. It predicts potential earth movements using the technique of nuclear magnetic resonance (NMR) to detect of underground water.
Geoscientists believe that movement of ground water causes about 80 per cent of landslides. The NMR technique, which was initially developed to provide images of organs and soft tissue in the human body through the skin, allows the presence and quantity of such water to be confirmed.
Furthermore it is faster, more accurate and cheaper than conventional drilling technology, says Li Zhenyu of the China University of Geosciences in Wuhan, who developed NMR's application to landslide detection.
Li, a geophysicist, led the world’s first attempt to observe landslide-prone massifs using NMR in the Three Gorges dam region of China's Hubei province between 2001 and 2003. And he and his colleagues have successfully predicted several landslides with the technology.
The new method costs only ten per cent of traditional drilling, and only needs 24 hours to collect data in one observation point, while the drill method needs up to 10 days, he says.
But most importantly, Li adds, nuclear magnetic resonance can obtain much more information on the movement of ground water than drilling technologies, as its accuracy on the number of drilling points.
Massive deforestation and construction of great dams, such as the Three Gorges project, have contributed to increasing numbers of landslides in China in recent years. According to the Xinhua news agency, landslides and mudflows caused 134 deaths and an economic loss of 3.7 billion yuan (more than US$446 million) in the first five months of 2003.
Nuclear magnetic resonance technology has great potential for landslide risk assessment in China, says Li. But he adds that a lack of capital and outdated landslide monitoring standards — which are based on the drilling method — have held back adoption of the technology.